Excretion of ropivacaine with breast milk during prolonged analgesia of a postoperative wound

The aim of our study was to evaluate the safety of ropivacaine given to lactating patients as a continuous infusion according to the selected local continuous wound infiltration (CWI) protocol after cesarean section (CS).

Materials and methods. Elective CSs were performed under spinal anesthesia with bupivacaine 5% -2 ml at the L2–L3 level. At the end of the operation, a 22 cm multiperforated catheter was placed in the surgical wound under the aponeurosis. 3 hours after spinal anesthesia a loading dose — 8 ml of 0.2% ropivacaine was administered and followed by continuous infusion at rate 4 mL/h for 48 hours. Aside from CWI, all patients received systemic anesthesia: acetaminophen 4000 mg per os, ketorolac 90 mg IV and rescue opioid — tramadol up to 400 mg (as-needed) daily. Breast milk (colostrum) samples were collected after 24 and 48 hours after a loading dose and were analyzed by gas chromatography with a mass selective detector for total ropivacaine concentrations.

Results. The number of patients included in the study was 8. During the study neither cases of the onset of symptoms associated with systemic toxicity of ropivacaine, nor allergic and infectious complications, were observed. The mean +- SD Cmax total colostrum ropivacaine concentration was 0.005 ± 0.002 (0.002 – 0.007) μg / ml.

Conclusion. In this limited sample, increasing the concentration or/and infusion rate seems to be a safe (for both mother and newborn) alternative or adjunct to standard systemic analgesia after CS in order to provide proper postoperative pain control.